The background of the present invention is illustrated in U.S. Pat. No. 5,586,605. More specifically, the background of the invention is shown in FIGS. 1, 2, 3, 7, 11, 12 and 13 of the subject patent where the wall contains a softer material on the outside, and a harder interior on the inside. The outer wythe of the wall is brick and mortar, and the same is secured in concrete. Where the tie is passed through the mortar, it will be seen that a two step or two diameter tie is recommended in the subject patents. Sometimes, a two step tie is not available at the job site, but it is still necessary to pass the helical tie through the mortar. Thus, it becomes highly desirable to have a "field fix kit" of the kind which will permit the tie specified for the job whether it be 4, 5, 6, 8 or 10 millimeters, or whether it be 75 millimeters and/or 100 millimeters in length. At job sites where a single tie is used, with a single diameter, and passing through a soft outer material such as mortar, the risk is that the joint will not survive a practical pull test, and where such joints might be ten to twenty percent of the project, a dangerous condition will be in the wall, despite the belief of those conducting the fix that adequate securement has been undertaken.
Particularly when random testing is to be undertaken, at the actual job site, a portion of the original helical tie may become loosened from the softer outer material. This can occur with ties which has been set into chemical resins, or initially dry fixed. After any such testing is made either in the back-up material or the exterior material, the tie which is in place needs to be reinforced.
In Applicant's related U.S. Pat. No. 5,687,801, there is disclosed an asymmetrical tie.
A larger portion of the tie is the later portion to be driven in, and normally will find itself in a mortar joint, or terra cotta, or other weaker exterior masonry, but the exterior needs to be engaged as firmly as the interior.
Not only is testing a problem, but in many instances, long lengths of tie need to be driven into soft or somewhat inconsistent materials like sandstone, multi-wythe brick, or terra cotta. With the vibration of the main tie, there is always the possibility that by the time the tie is set, engagement of the exterior portions do not have the necessary anchoring strength.